Comparisons of venus surface compositions with terrestrial ocean floor rocks
Statistical comparison of Venera and Vega lander x-ray fluorescence spectrometer measurements of the composition of the Venus surface with an extensive database of compositional data for terrestrial ocean floor rocks indicates that the Venera 14 data matches certain tholeiitic basalts from the Kane Fracture Zone (KFZ) in the Mid-Atlantic Ridge (22-25/sup 0/N) at high confidence levels. The tholeiites most similar to the Venera measurements are very primitive, low-calcium, high-alumina pillow basalts depleted in clinopyroxene, and are relatively unique to certain fracture zones in oceanic regions. If the Venera 14 analogy is valid, the implication is that certain Venus basaltic magmas have lost clinopyroxene at relatively high pressures by fractionation, perhaps within a deep source region. Comparisons of Venera 13 and Vega 2 data with oceanic rocks yield poorer matches. Venera 13 matches Loihi seamount alkali basalts, as well as potassic mafic rocks from oceanic island such as Tristan de Cunha. The best analogy to Vega 2 may be altered gabbros or basic lavas from terrestrial basic intrusions such as the Troodos ophiolite. The close similarity of a representative sample of Venera 14 material with distinctive ocean floor tholeiitic basalts suggests that deep magma storage regions exist on Venus, and that derivation of both tholeiitic and alkalic magmas from a single primitive parent may be an important process on Venus.
- Research Organization:
- NASA/Goddard, Greenbelt, MD (USA)
- OSTI ID:
- 5338952
- Journal Information:
- Sol. Syst. Res. (Engl. Transl.); (United States), Vol. 21:2; Other Information: Translated from Astron. Vestn.; 21: No. 2, 122-135(Apr-Jun 1987)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GENERAL PHYSICS
ATLANTIC OCEAN
PETROGENESIS
SEA BED
ROCKS
MINERALOGY
PETROCHEMISTRY
X-RAY FLUORESCENCE ANALYSIS
VENUS PLANET
PLANETARY EVOLUTION
COMPARATIVE EVALUATIONS
GEOCHEMICAL SURVEYS
MINERALS
SULFUR CONTENT
VENERA SPACE PROBES
CHEMICAL ANALYSIS
NONDESTRUCTIVE ANALYSIS
PLANETS
SEAS
SOLAR SYSTEM EVOLUTION
SPACE VEHICLES
SURFACE WATERS
SURVEYS
VEHICLES
X-RAY EMISSION ANALYSIS
640107* - Astrophysics & Cosmology- Planetary Phenomena